docs: def glob_handler(extension, folder=None, identifier=None):
      """Return a list of all files matching specified inputs.
  
      Parameters
      ----------
      extension : string
          File extension.
      folder : string (optional)
          Folder to search within. Default is None (current working
          directory).
      identifier : string
          Unique identifier. Default is None.
  
      Returns
      -------
      list of strings
          Full path of matching files.
      """
      filepaths = []
      if folder:
          # comment out [ and ]...
          folder = folder.replace("[", "?")
          folder = folder.replace("]", "*")
          folder = folder.replace("?", "[[]")
          folder = folder.replace("*", "[]]")
          glob_str = os.path.join(folder, "*" + extension)
      else:
          glob_str = "*" + extension + "*"
      for filepath in glob.glob(glob_str):
          if identifier:
              if identifier in filepath:
                  filepaths.append(filepath)
          else:
              filepaths.append(filepath)
      return filepaths